Best available cop



L. C. nowANo.

MAGNETIC ORE SEPARATR.' i v Arrucmou mia mi. 1. 1491s., u 1,803,398, lPiltlltd My 13 1919.

a :urns-sain J.I

S151, fr: www, I 1

naosce 'the vertical steel support columns 50 and 5 1,

V serve to steady oranchor the lower end of the electromagnetic unit.

With' the velectromagnetic unit structed as shown. and described the belts 35 may be removed without' disconnecting or changing the `adjustment of any parts expcthe wires leaning to the tous of the magnets, if. these 'wires are arranged. as shown in Fig. l1. In practice, however, the

wires will be so disposed, as for instance by being placed between the belts, that the lateach dischargngbelt 35 hns tenmay be removed without even disconnetting the wires.

As indicated in the plnn view (Fig, 4), its own. air of hoppers 41 und 42,and as both the belts cnn with convenience bedriven from the -snmc pulley '.39 (Fig. 2), it is advantageous to Inu-'e all 'four of these hoppers on the same side of the machine, even though the mate-4 rial gathered byone. pair maybe somewhat di'erent in grading from the material gathered by the other pair.

While I nm nwre that various changes in detail may be mude in the nparatus with?.

ont departing from the spirit of the present invention ns defined by the appended claims, the referred embodiment above described und illustrated in the drawings is one which luis been used with success.

I claim 1. An electromagnetic unit comprising a pair of coils, each provided with a magnetiznble core, and a magnetinable pole mugnetically `coc'iperating with said cores :md positioned-between said coils to form a pair of elongated magnetic air gaps, of sub- 'stantially the same size and shape and rigid' `spacers of non-magnetic material filling seid gaps-and holding seid cores and intermediatte polc in pro er spaced relation, substantiuliy ns descr .d.

2. An electromagnetic unit comprisinga paur of windings euch having amagnetiznhlc cure, nn intermediate coro magnctlzcd h v Suid windings and having a crosssection its alt least equal to that of both of said cores,

said `intermediate corc being adapted to copredetermined' width thereof.

3. An electromagnetic unit comprising a pair ol' coils, euch provided with n magnetiz- :ihlc core` n. nnlgnetizable pole magnetically ropcratng with said,.cores and positioned between said coils, said' coes'nnd said polo .boingprovided withcnlnrged pole pieces converging toward cach other to form nar- -maintain them in verging toward each other to form'narrdw air gaps, the intensity of the magnetic fields of which may be independently controlled and means inserted in each gap to prevent variations in the width thereof windings are energized: t

'5. An electromagnetic unit comprising a when the pair of coils, a magnetizablecore f or each` coil, un intermediate pole coperating mag netically with the cores, said cores and sald pole'being formed' with tapering gole tips conver ing toward euch other'at rig t angles to the enger axes of said cores and said pole,

and means inserted between the pole. tips to predetermined spaced relation. Q

6.' iin-'electromagnetic unlt comprising'a Vparir of' coils. a magnetizable core for each coil. an intermediate-pole coperating mag;

i yD() neticnlly with the cores, and 'forming wit the free ends thereof'elongeted magnetic I:nir gaps, n. spacer of non-magnetic material 1n nach nir gap and members of non-magnetic material fastened Ato the, ends of said.

cores und pole and between which said spacers nre clamped.

7. An electromagnetic unit comprising a pair of windings, a. magnetlzable core for nach winding provided` with inwardly dirented tapering` pole pieces, an intermediate core oopcrnting magnetically witlrthe other cores und provided. with an cnlnrgcdpole piece having tapering Vextemsions terminatmg ndjncentthe pole pieces of the first menl tioned cores to form'relntively narrow magnetic nir gaps.

8. An electromagnetic unit comprisin'f two outer cores en ch provided with enlar polc'pieces. tapering toward each other, an intermediate core having 'n cross sectiongat with tapering extensions4 termineting'V 'near` the Ypole pieces of the outer cores to' form relatively narrow magnetic air gaps, und n mugnctizing winding associated with each of the outer cores. i

ln testimony whereof I aiiix my signturc.

LEWIS c. ROWAND.

T .lenstequcl to the,combined.erosssectignslo `the outerccrcsnnd 'previded at'itsfteeend-'f- 

